Puppies are most commonly born with which types of intestinal worms?

• A. Roundworms and tapeworms
• B. Roundworms and hookworms
• C. Hookworms and pinworms
• D. Whipworms and tapeworms

Answer: (B)

Puppies are often born carrying intestinal parasites because certain worms can pass from the mother to her puppies before or around birth and through nursing. The two most common types involved are roundworms and hookworms. Roundworms can cross to the puppies in utero, and newborns can acquire them through the mother's milk. Hookworms can also be transmitted from dam to puppies very early, and they are especially concerning because they cause blood loss and anemia in young pups, which can be dangerous.

Because of these transmission routes, roundworms and hookworms are much more likely to be present at birth than other worms that require an intermediate host (like tapeworms) or take longer to establish in a young puppy (like whipworms). Tapeworms typically come from fleas or prey and are not usually present in newborns, while pinworms are uncommon in dogs. This is why the combination of roundworms and hookworms is the best answer for worms puppies are most commonly born with.